A simple and compact configuration for Digital Holography of microscopic reflecting structures is presented. The proposed technique employs a Wire grid polarizer (WGP) to obtain two orthogonally polarized light beams serving as reference and object information. The salient features of the proposed technique include in-line common path configuration, which provides less phase noise and less distortion from ambient vibrations. As demonstrated, the proposed design has the potential to implement Polarization Phase Shifting. © 2020, Springer Nature Singapore Pte Ltd.